fix: background PocketIC output to files

crates/icp/src/network/directory.rs

@@ -214,6 +214,16 @@ impl NetworkRootPaths {
     pub fn pocketic_port_file(&self) -> PathBuf {
         self.pocketic_dir().join("port")
     }
+
+    /// PocketIC writes its stdout to this file.
+    pub fn pocketic_stdout_file(&self) -> PathBuf {
+        self.pocketic_dir().join("stdout.log")
+    }
+
+    /// PocketIC writes its stderr to this file.
+    pub fn pocketic_stderr_file(&self) -> PathBuf {
+        self.pocketic_dir().join("stderr.log")
+    }
 }
 
 impl PathsAccess for NetworkRootPaths {

crates/icp/src/network/managed/pocketic.rs

@@ -69,14 +69,22 @@ pub struct PocketIcInstance {
     pub root_key: String,
 }
 
-pub fn spawn_pocketic(pocketic_path: &Path, port_file: &Path) -> tokio::process::Child {
+pub fn spawn_pocketic(
+    pocketic_path: &Path,
+    port_file: &Path,
+    stdout_file: &Path,
+    stderr_file: &Path,
+) -> tokio::process::Child {
     let mut cmd = tokio::process::Command::new(pocketic_path);
     cmd.arg("--port-file");
     cmd.arg(port_file.as_os_str());
     cmd.args(["--ttl", "2592000", "--log-levels", "error"]);
 
-    cmd.stdout(std::process::Stdio::inherit());
-    cmd.stderr(std::process::Stdio::inherit());
+    let stdout = std::fs::File::create(stdout_file).expect("Failed to create stdout file.");
+    let stderr = std::fs::File::create(stderr_file).expect("Failed to create stderr file.");
+    cmd.stdout(std::process::Stdio::from(stdout));
+    cmd.stderr(std::process::Stdio::from(stderr));
+
     #[cfg(unix)]
     {
         cmd.process_group(0);

crates/icp/src/network/managed/run.rs

@@ -101,7 +101,12 @@ async fn run_pocketic(
             }
             create_dir_all(&root.state_dir()).context(CreateDirAllSnafu)?;
 
-            let child = c_child.insert(spawn_pocketic(pocketic_path, &port_file));
+            let child = c_child.insert(spawn_pocketic(
+                pocketic_path,
+                &port_file,
+                &root.pocketic_stdout_file(),
+                &root.pocketic_stderr_file(),
+            ));
             let pocketic_port = wait_for_port(&port_file, child).await?;
             eprintln!("PocketIC started on port {pocketic_port}");
             let instance = initialize_pocketic(